1. Technical Field
This invention relates generally to systems and methods for monitoring ergonomic motion, and more particularly to a system and method for learning and teaching a preferred repetitive movement by establishing a spatial region and monitoring entry or exit of the spatial region by way of a feedback alarm.
2. Background Art
Athletes are constantly looking for ways to improve their technique. This is especially true in the game of golf. To paraphrase Homer Kelley, author of The Golfing Machine, a golf stroke is not a basic procedure, but rather basic geometry involving the geometry of the circle and the physics of rotation. In other words, golf is not a game of proper positions, but rather a game of proper alignment. Many a weekend golfer becomes frustrated when told to xe2x80x9ckeep your arm straightxe2x80x9d or xe2x80x9ckeep your head downxe2x80x9d without a sufficient explanation as to why. It is of little comfort when an advisor""s only justification is xe2x80x9cbecause Jack Nicklaus did it that way.xe2x80x9d
However, with a little bit of scientific analysis, the golf stroke, as does all athletic activity, becomes understandable and may be analyzed with more precision. This is true because the fundamental laws of physics govern athletic activity just as they do the tasks of everyday life. Simply put, everyone must obey the laws of physics in every activity. They govern life in the twenty-first century just as they did in the first century. Understanding their effect on the golf swing brings clarity to the mystery of golf. In the words of Kelley, xe2x80x9cWhen the facts are understood, the illusions not only cease to mislead but can be utilized.xe2x80x9d
This is best illustrated by way of example. A simple example is the concept of the swing plane in golf. Referring now to FIG. 1, illustrated therein is a golfer 100 addressing a ball 101. The club shaft 102 represents the first line 104 in the swing plane equation. The imaginary line running from the ball 101 to the target 106, known as the xe2x80x9ctarget linexe2x80x9d 103, forms the second line. To swing a golf club with maximum efficiency and mechanical advantage, these two linesxe2x80x94the shaft line 104 and the target line 103xe2x80x94must always intersect. In geometric terms, two intersecting lines are known as xe2x80x9ccoplanarxe2x80x9d lines. Many teaching professionals and scientific analysts suggest that the optimum golf swing is one in which the golfer always keeps the club shaft 102, and thus the line 104 represented by the club shaft 102, coplanar to the target line 103.
To see why this would appear to be true, imagine what would happen if the two lines 103, 104 were not coplanar, i.e. intersecting, at the moment the golfer 100 tried to make contact with the ball 101 (known as the xe2x80x9cimpact pointxe2x80x9d). In other words, if the shaft line 104 did not point to and intersect the target line 103 when the club head 105 got to the ball 101, the golfer 100 would miss, or xe2x80x9cwhiffxe2x80x9d, the ball 101. Whiffing the ball, as anyone who has played golf knows, is responsible for many a profane word, thrown or broken club and unpleasant disposition.
The golfer has only a finite amount of energy with which to strike the ball. If the club shaft and target line become xe2x80x9cskewxe2x80x9d, i.e. not coplanar, then the golfer would need to use some of that finite power to physically redirect the club into a coplanar alignment with the target line. If he does not do so, he will miss the ball. Energy that is used in redirection cannot be used to propel the ball towards the target. Simply put, when the club gets out of plane, the golfer loses both control and distance. Many teachers suggest, therefore, that the easiest way to swing, with the most power and most mechanical advantage, within the limits of human motion, is thus to always keep the club shaft and target line coplanar. This coplanar relationship is generally known as being xe2x80x9con planexe2x80x9d.
Golf instructors who are proponents of this approach have developed numerous teaching aids to help the golfer stay on plane. One such device is a rigid circle, often made of plastic pipe. The circle represents one plane upon which the golfer swings. The problem with this solution is that the circle represents one fixed plane at a fixed angle. For the human golfer, it has been suggested the plane angle actually shifts to a more upright angle during the back swing, and then to a flatter angle during the downswing. In other words, while the golfer is swinging, the club shaft and target line are always coplanar, but the angle of that plane actually changes relative to the ground. With the plastic pipe, however, the angle of the plastic circle stays constant. Thus, when the golfer is in a portion of the swing in which the angle of his plane is greater than that of the plastic circle, the circle ceases to be effective as a training aid. He may still have the club xe2x80x9cin planexe2x80x9d, yet will not be in contact with the circular ring. This is illustrated in FIG. 2.
Another such training aid is a rigid arm that couples to the center of the club shaft and affixes to a wall. When the golfer swings, the rigid arm causes the shaft to trace a circular motion that resembles the swing. The problem with this aid is that it is based upon the premise that the head is the center of the swing. Many teachers suggest, however, that in reality, the center of the swing is (for the right handed golfer) much closer to the left shoulder. (The fundamental structure in the golf swing being a form III lever assembly formed by the left shoulder, the hands and the club head.) When the left shoulder moves back away from the target line during the follow through, the rigid arm coupled to the fixed wall is incapable of following the shoulder. Consequently, the golfer is thrown off plane during the follow through.
While swing plane works well as one illustrative alignment, there are many other alignments that must be monitored as well. These include shoulder alignment, torso alignment, hip alignment, arm alignment, hand alignment, and head alignment, just to name a few. Additionally, some professionals subscribe to alternate approaches. They may teach techniques that do not embrace the coplanar approach. They instead teach systems that each have their own signature alignments.
It would be advantageous to be able monitor these alignments of the golf swing, as well as provide feedback to the golfer when a preferred motion was not made. Additionally, there are similar needs with respect to other ergonomic motions, including other sports, physical therapy, work related human motion, animal training and the like. There is thus a need for a system that is capable of monitoring human ergonomic motion and providing feedback to assist the user in learning preferred techniques of motion.